syz.3.26118[17669] is installing a program with bpf_probe_write_user helper that may corrupt user memory!
==================================================================
BUG: KCSAN: data-race in _prb_read_valid / prb_reserve

write to 0xffffffff867302f8 of 8 bytes by task 11 on cpu 0:
 prb_reserve+0x740/0xb60
 vprintk_store+0x558/0x870 kernel/printk/printk.c:2326
 vprintk_emit+0x15e/0x680 kernel/printk/printk.c:2408
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2447
 vprintk+0x75/0x80 kernel/printk/printk_safe.c:86
 _printk+0x7a/0xa0 kernel/printk/printk.c:2457
 __ext4_msg+0x18e/0x1a0 fs/ext4/super.c:998
 mpage_map_and_submit_extent fs/ext4/inode.c:2296 [inline]
 ext4_do_writepages+0x19e4/0x2130 fs/ext4/inode.c:2735
 ext4_writepages+0x159/0x2e0 fs/ext4/inode.c:2824
 do_writepages+0x1d8/0x480 mm/page-writeback.c:2702
 __writeback_single_inode+0x89/0x850 fs/fs-writeback.c:1680
 writeback_sb_inodes+0x461/0xa30 fs/fs-writeback.c:1976
 wb_writeback+0x262/0x640 fs/fs-writeback.c:2156
 wb_do_writeback fs/fs-writeback.c:2303 [inline]
 wb_workfn+0x1a8/0x940 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3310
 worker_thread+0x51d/0x6f0 kernel/workqueue.c:3391
 kthread+0x1d1/0x210 kernel/kthread.c:389
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

read to 0xffffffff867302f8 of 8 bytes by task 17669 on cpu 1:
 desc_read kernel/printk/printk_ringbuffer.c:486 [inline]
 prb_first_seq kernel/printk/printk_ringbuffer.c:1957 [inline]
 _prb_read_valid+0x3bb/0xba0 kernel/printk/printk_ringbuffer.c:2114
 prb_read_valid+0x3d/0x60 kernel/printk/printk_ringbuffer.c:2182
 printk_get_next_message+0xd4/0x710 kernel/printk/printk.c:2989
 console_emit_next_record kernel/printk/printk.c:3076 [inline]
 console_flush_all+0x28a/0x770 kernel/printk/printk.c:3210
 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline]
 console_unlock+0xab/0x330 kernel/printk/printk.c:3309
 vprintk_emit+0x3f4/0x680 kernel/printk/printk.c:2432
 vprintk_default+0x26/0x30 kernel/printk/printk.c:2447
 vprintk+0x75/0x80 kernel/printk/printk_safe.c:86
 _printk+0x7a/0xa0 kernel/printk/printk.c:2457
 bpf_get_probe_write_proto+0x8b/0x90 kernel/trace/bpf_trace.c:365
 bpf_tracing_func_proto+0x596/0x790 kernel/trace/bpf_trace.c:1490
 raw_tp_prog_func_proto+0x65/0xc0 kernel/trace/bpf_trace.c:1973
 get_helper_proto kernel/bpf/verifier.c:10641 [inline]
 mark_fastcall_pattern_for_call kernel/bpf/verifier.c:16511 [inline]
 mark_fastcall_patterns+0x566/0xd10 kernel/bpf/verifier.c:16622
 bpf_check+0x3ec1/0xd5e0 kernel/bpf/verifier.c:22661
 bpf_prog_load+0xed4/0x1070 kernel/bpf/syscall.c:2947
 __sys_bpf+0x463/0x7a0 kernel/bpf/syscall.c:5790
 __do_sys_bpf kernel/bpf/syscall.c:5897 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5895 [inline]
 __x64_sys_bpf+0x43/0x50 kernel/bpf/syscall.c:5895
 x64_sys_call+0x2914/0x2dc0 arch/x86/include/generated/asm/syscalls_64.h:322
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000009c65 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 17669 Comm: syz.3.26118 Not tainted 6.13.0-rc3-syzkaller-00289-g48f506ad0b68 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================
syz.3.26118[17669] is installing a program with bpf_probe_write_user helper that may corrupt user memory!
syz.3.26118[17669] is installing a program with bpf_probe_write_user helper that may corrupt user memory!